Reservoirs suffer winterkill

Colorado Parks and Wildlife field staff have confirmed that a large number of fish died over the winter at Lake Henry.

Comment

By By Staff Reports

LA Junta Tribune - La Junta, CO

By By Staff Reports

Posted Feb. 9, 2013 at 11:00 AM

By By Staff Reports

Posted Feb. 9, 2013 at 11:00 AM

Colorado Parks and Wildlife field staff have confirmed that a large number of fish died over the winter at Lake Henry.

"We started seeing dead fish when the ice melted," said Jim Ramsay, a Colorado Parks and Wildlife aquatic biologist from Lamar. "This is not too surprising, given the extreme low-water conditions we saw going into winter."

"At this time we are unsure of the extent of the fish kill. It is possible there are still game fish that survived at Henry. The majority of the dead fish we saw were forage fish. There were some dead catfish and wipers as well, but we did not see many dead crappie, saugeye, or larger channel catfish," said Ramsay.

Winter fish kills can occur when shallow reservoirs ice-over and oxygen levels drop. Low oxygen levels result from a combination of factors. The ice prevents air from mixing with the water, thereby limiting the exchange of oxygen at the surface. Ice can also reduce sunlight from reaching aquatic plant life that would otherwise produce oxygen through the process of photosynthesis.

"We plan to do sampling at Henry and other local reservoirs to assess overall conditions," said Ramsay.

Doug Krieger, senior aquatic biologist for the Southeast Region, said, "Unless we see some significant changes, we expect drought conditions could have a negative impact on fishing in some waters this year. Drought conditions are likely going to be more extreme than last year due to current low reservoir storage levels. As such, Colorado Parks and Wildlife will be monitoring water levels and angler access and adjust management accordingly."